ATF spokeswoman Franceska Perot says it could take several more weeks to figure out what caused the massive explosion and the fire that burned before that.

State records reportedly show the West Fertilizer plant had a yearly capacity of 2,400 tons of potentially explosive ammonium nitrate.

The ATF says investigators have only ruled out that the weather played no role in the blast.

The U.S. Army Corp of Engineers arrived on scene Monday to assist investigators in assessing the 93 by 10 foot crater.

On Monday, the U.S. Homeland Security Department said The West Fertilizer Co. facility isn’t currently regulated under a department program that’s designed to reduce the risk of terrorism at certain high-risk chemical facilities.

CBS-11 has learned Homeland Security is now looking into whether the facility should have submitted paperwork about the chemicals stored at the plant to determine if it should be regulated.

Sources say if the facility doesn’t submit paperwork and should have, the government could impose a fine or shut down operations at the site.

Scott Deatherage has been an environmental lawyer for 25 years and says, “If you knowingly didn’t comply and knowingly put somebody at risk or at danger, called the knowing in danger provisions in the environmental statutes, there could be a criminal prosecution of the company.”

But no accusations or charges have been leveled against the company.

The CBS-11 I-Team spoke with the owner of the company, Donald Adair, by phone late Monday afternoon.

Regarding the Department of Homeland Security, Adair said, “I don’t want to comment. But there is a lot of wrong information out there. A lot of what the media is reporting is wrong information.”

He says his attorneys have advised him not to say anything.

Adair says, they won’t let him back on the grounds just yet, and he says he is “still not sleeping at night.”

As for Cindy Grones, she is not angry.

Grones says, “I’m sure the owner of the company, he’s pretty sad and stuff about all this happening. He didn’t want this to happen.”